Commit | Line | Data |
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5b1158e9 JK |
1 | /* NAT for netfilter; shared with compatibility layer. */ |
2 | ||
3 | /* (C) 1999-2001 Paul `Rusty' Russell | |
4 | * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | */ | |
10 | ||
11 | #include <linux/module.h> | |
12 | #include <linux/types.h> | |
13 | #include <linux/timer.h> | |
14 | #include <linux/skbuff.h> | |
15 | #include <linux/vmalloc.h> | |
16 | #include <net/checksum.h> | |
17 | #include <net/icmp.h> | |
18 | #include <net/ip.h> | |
19 | #include <net/tcp.h> /* For tcp_prot in getorigdst */ | |
20 | #include <linux/icmp.h> | |
21 | #include <linux/udp.h> | |
22 | #include <linux/jhash.h> | |
23 | ||
24 | #include <linux/netfilter_ipv4.h> | |
25 | #include <net/netfilter/nf_conntrack.h> | |
26 | #include <net/netfilter/nf_conntrack_core.h> | |
27 | #include <net/netfilter/nf_nat.h> | |
28 | #include <net/netfilter/nf_nat_protocol.h> | |
29 | #include <net/netfilter/nf_nat_core.h> | |
30 | #include <net/netfilter/nf_nat_helper.h> | |
31 | #include <net/netfilter/nf_conntrack_helper.h> | |
32 | #include <net/netfilter/nf_conntrack_l3proto.h> | |
33 | #include <net/netfilter/nf_conntrack_l4proto.h> | |
34 | ||
35 | #if 0 | |
36 | #define DEBUGP printk | |
37 | #else | |
38 | #define DEBUGP(format, args...) | |
39 | #endif | |
40 | ||
41 | static DEFINE_RWLOCK(nf_nat_lock); | |
42 | ||
43 | static struct nf_conntrack_l3proto *l3proto = NULL; | |
44 | ||
45 | /* Calculated at init based on memory size */ | |
46 | static unsigned int nf_nat_htable_size; | |
47 | ||
48 | static struct list_head *bysource; | |
49 | ||
50 | #define MAX_IP_NAT_PROTO 256 | |
51 | static struct nf_nat_protocol *nf_nat_protos[MAX_IP_NAT_PROTO]; | |
52 | ||
53 | static inline struct nf_nat_protocol * | |
54 | __nf_nat_proto_find(u_int8_t protonum) | |
55 | { | |
56 | return nf_nat_protos[protonum]; | |
57 | } | |
58 | ||
59 | struct nf_nat_protocol * | |
60 | nf_nat_proto_find_get(u_int8_t protonum) | |
61 | { | |
62 | struct nf_nat_protocol *p; | |
63 | ||
64 | /* we need to disable preemption to make sure 'p' doesn't get | |
65 | * removed until we've grabbed the reference */ | |
66 | preempt_disable(); | |
67 | p = __nf_nat_proto_find(protonum); | |
68 | if (!try_module_get(p->me)) | |
69 | p = &nf_nat_unknown_protocol; | |
70 | preempt_enable(); | |
71 | ||
72 | return p; | |
73 | } | |
74 | EXPORT_SYMBOL_GPL(nf_nat_proto_find_get); | |
75 | ||
76 | void | |
77 | nf_nat_proto_put(struct nf_nat_protocol *p) | |
78 | { | |
79 | module_put(p->me); | |
80 | } | |
81 | EXPORT_SYMBOL_GPL(nf_nat_proto_put); | |
82 | ||
83 | /* We keep an extra hash for each conntrack, for fast searching. */ | |
84 | static inline unsigned int | |
85 | hash_by_src(const struct nf_conntrack_tuple *tuple) | |
86 | { | |
87 | /* Original src, to ensure we map it consistently if poss. */ | |
88 | return jhash_3words((__force u32)tuple->src.u3.ip, tuple->src.u.all, | |
89 | tuple->dst.protonum, 0) % nf_nat_htable_size; | |
90 | } | |
91 | ||
92 | /* Noone using conntrack by the time this called. */ | |
93 | static void nf_nat_cleanup_conntrack(struct nf_conn *conn) | |
94 | { | |
95 | struct nf_conn_nat *nat; | |
96 | if (!(conn->status & IPS_NAT_DONE_MASK)) | |
97 | return; | |
98 | ||
99 | nat = nfct_nat(conn); | |
100 | write_lock_bh(&nf_nat_lock); | |
101 | list_del(&nat->info.bysource); | |
102 | write_unlock_bh(&nf_nat_lock); | |
103 | } | |
104 | ||
105 | /* Is this tuple already taken? (not by us) */ | |
106 | int | |
107 | nf_nat_used_tuple(const struct nf_conntrack_tuple *tuple, | |
108 | const struct nf_conn *ignored_conntrack) | |
109 | { | |
110 | /* Conntrack tracking doesn't keep track of outgoing tuples; only | |
111 | incoming ones. NAT means they don't have a fixed mapping, | |
112 | so we invert the tuple and look for the incoming reply. | |
113 | ||
114 | We could keep a separate hash if this proves too slow. */ | |
115 | struct nf_conntrack_tuple reply; | |
116 | ||
117 | nf_ct_invert_tuplepr(&reply, tuple); | |
118 | return nf_conntrack_tuple_taken(&reply, ignored_conntrack); | |
119 | } | |
120 | EXPORT_SYMBOL(nf_nat_used_tuple); | |
121 | ||
122 | /* If we source map this tuple so reply looks like reply_tuple, will | |
123 | * that meet the constraints of range. */ | |
124 | static int | |
125 | in_range(const struct nf_conntrack_tuple *tuple, | |
126 | const struct nf_nat_range *range) | |
127 | { | |
128 | struct nf_nat_protocol *proto; | |
129 | ||
130 | proto = __nf_nat_proto_find(tuple->dst.protonum); | |
131 | /* If we are supposed to map IPs, then we must be in the | |
132 | range specified, otherwise let this drag us onto a new src IP. */ | |
133 | if (range->flags & IP_NAT_RANGE_MAP_IPS) { | |
134 | if (ntohl(tuple->src.u3.ip) < ntohl(range->min_ip) || | |
135 | ntohl(tuple->src.u3.ip) > ntohl(range->max_ip)) | |
136 | return 0; | |
137 | } | |
138 | ||
139 | if (!(range->flags & IP_NAT_RANGE_PROTO_SPECIFIED) || | |
140 | proto->in_range(tuple, IP_NAT_MANIP_SRC, | |
141 | &range->min, &range->max)) | |
142 | return 1; | |
143 | ||
144 | return 0; | |
145 | } | |
146 | ||
147 | static inline int | |
148 | same_src(const struct nf_conn *ct, | |
149 | const struct nf_conntrack_tuple *tuple) | |
150 | { | |
151 | const struct nf_conntrack_tuple *t; | |
152 | ||
153 | t = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple; | |
154 | return (t->dst.protonum == tuple->dst.protonum && | |
155 | t->src.u3.ip == tuple->src.u3.ip && | |
156 | t->src.u.all == tuple->src.u.all); | |
157 | } | |
158 | ||
159 | /* Only called for SRC manip */ | |
160 | static int | |
161 | find_appropriate_src(const struct nf_conntrack_tuple *tuple, | |
162 | struct nf_conntrack_tuple *result, | |
163 | const struct nf_nat_range *range) | |
164 | { | |
165 | unsigned int h = hash_by_src(tuple); | |
166 | struct nf_conn_nat *nat; | |
167 | struct nf_conn *ct; | |
168 | ||
169 | read_lock_bh(&nf_nat_lock); | |
170 | list_for_each_entry(nat, &bysource[h], info.bysource) { | |
171 | ct = (struct nf_conn *)((char *)nat - offsetof(struct nf_conn, data)); | |
172 | if (same_src(ct, tuple)) { | |
173 | /* Copy source part from reply tuple. */ | |
174 | nf_ct_invert_tuplepr(result, | |
175 | &ct->tuplehash[IP_CT_DIR_REPLY].tuple); | |
176 | result->dst = tuple->dst; | |
177 | ||
178 | if (in_range(result, range)) { | |
179 | read_unlock_bh(&nf_nat_lock); | |
180 | return 1; | |
181 | } | |
182 | } | |
183 | } | |
184 | read_unlock_bh(&nf_nat_lock); | |
185 | return 0; | |
186 | } | |
187 | ||
188 | /* For [FUTURE] fragmentation handling, we want the least-used | |
189 | src-ip/dst-ip/proto triple. Fairness doesn't come into it. Thus | |
190 | if the range specifies 1.2.3.4 ports 10000-10005 and 1.2.3.5 ports | |
191 | 1-65535, we don't do pro-rata allocation based on ports; we choose | |
192 | the ip with the lowest src-ip/dst-ip/proto usage. | |
193 | */ | |
194 | static void | |
195 | find_best_ips_proto(struct nf_conntrack_tuple *tuple, | |
196 | const struct nf_nat_range *range, | |
197 | const struct nf_conn *ct, | |
198 | enum nf_nat_manip_type maniptype) | |
199 | { | |
200 | __be32 *var_ipp; | |
201 | /* Host order */ | |
202 | u_int32_t minip, maxip, j; | |
203 | ||
204 | /* No IP mapping? Do nothing. */ | |
205 | if (!(range->flags & IP_NAT_RANGE_MAP_IPS)) | |
206 | return; | |
207 | ||
208 | if (maniptype == IP_NAT_MANIP_SRC) | |
209 | var_ipp = &tuple->src.u3.ip; | |
210 | else | |
211 | var_ipp = &tuple->dst.u3.ip; | |
212 | ||
213 | /* Fast path: only one choice. */ | |
214 | if (range->min_ip == range->max_ip) { | |
215 | *var_ipp = range->min_ip; | |
216 | return; | |
217 | } | |
218 | ||
219 | /* Hashing source and destination IPs gives a fairly even | |
220 | * spread in practice (if there are a small number of IPs | |
221 | * involved, there usually aren't that many connections | |
222 | * anyway). The consistency means that servers see the same | |
223 | * client coming from the same IP (some Internet Banking sites | |
224 | * like this), even across reboots. */ | |
225 | minip = ntohl(range->min_ip); | |
226 | maxip = ntohl(range->max_ip); | |
227 | j = jhash_2words((__force u32)tuple->src.u3.ip, | |
228 | (__force u32)tuple->dst.u3.ip, 0); | |
229 | *var_ipp = htonl(minip + j % (maxip - minip + 1)); | |
230 | } | |
231 | ||
232 | /* Manipulate the tuple into the range given. For NF_IP_POST_ROUTING, | |
233 | * we change the source to map into the range. For NF_IP_PRE_ROUTING | |
234 | * and NF_IP_LOCAL_OUT, we change the destination to map into the | |
235 | * range. It might not be possible to get a unique tuple, but we try. | |
236 | * At worst (or if we race), we will end up with a final duplicate in | |
237 | * __ip_conntrack_confirm and drop the packet. */ | |
238 | static void | |
239 | get_unique_tuple(struct nf_conntrack_tuple *tuple, | |
240 | const struct nf_conntrack_tuple *orig_tuple, | |
241 | const struct nf_nat_range *range, | |
242 | struct nf_conn *ct, | |
243 | enum nf_nat_manip_type maniptype) | |
244 | { | |
245 | struct nf_nat_protocol *proto; | |
246 | ||
247 | /* 1) If this srcip/proto/src-proto-part is currently mapped, | |
248 | and that same mapping gives a unique tuple within the given | |
249 | range, use that. | |
250 | ||
251 | This is only required for source (ie. NAT/masq) mappings. | |
252 | So far, we don't do local source mappings, so multiple | |
253 | manips not an issue. */ | |
254 | if (maniptype == IP_NAT_MANIP_SRC) { | |
255 | if (find_appropriate_src(orig_tuple, tuple, range)) { | |
256 | DEBUGP("get_unique_tuple: Found current src map\n"); | |
41f4689a EL |
257 | if (!(range->flags & IP_NAT_RANGE_PROTO_RANDOM)) |
258 | if (!nf_nat_used_tuple(tuple, ct)) | |
259 | return; | |
5b1158e9 JK |
260 | } |
261 | } | |
262 | ||
263 | /* 2) Select the least-used IP/proto combination in the given | |
264 | range. */ | |
265 | *tuple = *orig_tuple; | |
266 | find_best_ips_proto(tuple, range, ct, maniptype); | |
267 | ||
268 | /* 3) The per-protocol part of the manip is made to map into | |
269 | the range to make a unique tuple. */ | |
270 | ||
271 | proto = nf_nat_proto_find_get(orig_tuple->dst.protonum); | |
272 | ||
41f4689a EL |
273 | /* Change protocol info to have some randomization */ |
274 | if (range->flags & IP_NAT_RANGE_PROTO_RANDOM) { | |
275 | proto->unique_tuple(tuple, range, maniptype, ct); | |
276 | nf_nat_proto_put(proto); | |
277 | return; | |
278 | } | |
279 | ||
5b1158e9 JK |
280 | /* Only bother mapping if it's not already in range and unique */ |
281 | if ((!(range->flags & IP_NAT_RANGE_PROTO_SPECIFIED) || | |
282 | proto->in_range(tuple, maniptype, &range->min, &range->max)) && | |
283 | !nf_nat_used_tuple(tuple, ct)) { | |
284 | nf_nat_proto_put(proto); | |
285 | return; | |
286 | } | |
287 | ||
288 | /* Last change: get protocol to try to obtain unique tuple. */ | |
289 | proto->unique_tuple(tuple, range, maniptype, ct); | |
290 | ||
291 | nf_nat_proto_put(proto); | |
292 | } | |
293 | ||
294 | unsigned int | |
295 | nf_nat_setup_info(struct nf_conn *ct, | |
296 | const struct nf_nat_range *range, | |
297 | unsigned int hooknum) | |
298 | { | |
299 | struct nf_conntrack_tuple curr_tuple, new_tuple; | |
300 | struct nf_conn_nat *nat = nfct_nat(ct); | |
301 | struct nf_nat_info *info = &nat->info; | |
302 | int have_to_hash = !(ct->status & IPS_NAT_DONE_MASK); | |
303 | enum nf_nat_manip_type maniptype = HOOK2MANIP(hooknum); | |
304 | ||
305 | NF_CT_ASSERT(hooknum == NF_IP_PRE_ROUTING || | |
306 | hooknum == NF_IP_POST_ROUTING || | |
307 | hooknum == NF_IP_LOCAL_IN || | |
308 | hooknum == NF_IP_LOCAL_OUT); | |
309 | BUG_ON(nf_nat_initialized(ct, maniptype)); | |
310 | ||
311 | /* What we've got will look like inverse of reply. Normally | |
312 | this is what is in the conntrack, except for prior | |
313 | manipulations (future optimization: if num_manips == 0, | |
314 | orig_tp = | |
315 | conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple) */ | |
316 | nf_ct_invert_tuplepr(&curr_tuple, | |
317 | &ct->tuplehash[IP_CT_DIR_REPLY].tuple); | |
318 | ||
319 | get_unique_tuple(&new_tuple, &curr_tuple, range, ct, maniptype); | |
320 | ||
321 | if (!nf_ct_tuple_equal(&new_tuple, &curr_tuple)) { | |
322 | struct nf_conntrack_tuple reply; | |
323 | ||
324 | /* Alter conntrack table so will recognize replies. */ | |
325 | nf_ct_invert_tuplepr(&reply, &new_tuple); | |
326 | nf_conntrack_alter_reply(ct, &reply); | |
327 | ||
328 | /* Non-atomic: we own this at the moment. */ | |
329 | if (maniptype == IP_NAT_MANIP_SRC) | |
330 | ct->status |= IPS_SRC_NAT; | |
331 | else | |
332 | ct->status |= IPS_DST_NAT; | |
333 | } | |
334 | ||
335 | /* Place in source hash if this is the first time. */ | |
336 | if (have_to_hash) { | |
337 | unsigned int srchash; | |
338 | ||
339 | srchash = hash_by_src(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); | |
340 | write_lock_bh(&nf_nat_lock); | |
341 | list_add(&info->bysource, &bysource[srchash]); | |
342 | write_unlock_bh(&nf_nat_lock); | |
343 | } | |
344 | ||
345 | /* It's done. */ | |
346 | if (maniptype == IP_NAT_MANIP_DST) | |
347 | set_bit(IPS_DST_NAT_DONE_BIT, &ct->status); | |
348 | else | |
349 | set_bit(IPS_SRC_NAT_DONE_BIT, &ct->status); | |
350 | ||
351 | return NF_ACCEPT; | |
352 | } | |
353 | EXPORT_SYMBOL(nf_nat_setup_info); | |
354 | ||
355 | /* Returns true if succeeded. */ | |
356 | static int | |
357 | manip_pkt(u_int16_t proto, | |
358 | struct sk_buff **pskb, | |
359 | unsigned int iphdroff, | |
360 | const struct nf_conntrack_tuple *target, | |
361 | enum nf_nat_manip_type maniptype) | |
362 | { | |
363 | struct iphdr *iph; | |
364 | struct nf_nat_protocol *p; | |
365 | ||
366 | if (!skb_make_writable(pskb, iphdroff + sizeof(*iph))) | |
367 | return 0; | |
368 | ||
369 | iph = (void *)(*pskb)->data + iphdroff; | |
370 | ||
371 | /* Manipulate protcol part. */ | |
372 | p = nf_nat_proto_find_get(proto); | |
373 | if (!p->manip_pkt(pskb, iphdroff, target, maniptype)) { | |
374 | nf_nat_proto_put(p); | |
375 | return 0; | |
376 | } | |
377 | nf_nat_proto_put(p); | |
378 | ||
379 | iph = (void *)(*pskb)->data + iphdroff; | |
380 | ||
381 | if (maniptype == IP_NAT_MANIP_SRC) { | |
382 | nf_csum_replace4(&iph->check, iph->saddr, target->src.u3.ip); | |
383 | iph->saddr = target->src.u3.ip; | |
384 | } else { | |
385 | nf_csum_replace4(&iph->check, iph->daddr, target->dst.u3.ip); | |
386 | iph->daddr = target->dst.u3.ip; | |
387 | } | |
388 | return 1; | |
389 | } | |
390 | ||
391 | /* Do packet manipulations according to nf_nat_setup_info. */ | |
392 | unsigned int nf_nat_packet(struct nf_conn *ct, | |
393 | enum ip_conntrack_info ctinfo, | |
394 | unsigned int hooknum, | |
395 | struct sk_buff **pskb) | |
396 | { | |
397 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); | |
398 | unsigned long statusbit; | |
399 | enum nf_nat_manip_type mtype = HOOK2MANIP(hooknum); | |
400 | ||
401 | if (mtype == IP_NAT_MANIP_SRC) | |
402 | statusbit = IPS_SRC_NAT; | |
403 | else | |
404 | statusbit = IPS_DST_NAT; | |
405 | ||
406 | /* Invert if this is reply dir. */ | |
407 | if (dir == IP_CT_DIR_REPLY) | |
408 | statusbit ^= IPS_NAT_MASK; | |
409 | ||
410 | /* Non-atomic: these bits don't change. */ | |
411 | if (ct->status & statusbit) { | |
412 | struct nf_conntrack_tuple target; | |
413 | ||
414 | /* We are aiming to look like inverse of other direction. */ | |
415 | nf_ct_invert_tuplepr(&target, &ct->tuplehash[!dir].tuple); | |
416 | ||
417 | if (!manip_pkt(target.dst.protonum, pskb, 0, &target, mtype)) | |
418 | return NF_DROP; | |
419 | } | |
420 | return NF_ACCEPT; | |
421 | } | |
422 | EXPORT_SYMBOL_GPL(nf_nat_packet); | |
423 | ||
424 | /* Dir is direction ICMP is coming from (opposite to packet it contains) */ | |
425 | int nf_nat_icmp_reply_translation(struct nf_conn *ct, | |
426 | enum ip_conntrack_info ctinfo, | |
427 | unsigned int hooknum, | |
428 | struct sk_buff **pskb) | |
429 | { | |
430 | struct { | |
431 | struct icmphdr icmp; | |
432 | struct iphdr ip; | |
433 | } *inside; | |
434 | struct nf_conntrack_tuple inner, target; | |
435 | int hdrlen = (*pskb)->nh.iph->ihl * 4; | |
436 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); | |
437 | unsigned long statusbit; | |
438 | enum nf_nat_manip_type manip = HOOK2MANIP(hooknum); | |
439 | ||
440 | if (!skb_make_writable(pskb, hdrlen + sizeof(*inside))) | |
441 | return 0; | |
442 | ||
443 | inside = (void *)(*pskb)->data + (*pskb)->nh.iph->ihl*4; | |
444 | ||
445 | /* We're actually going to mangle it beyond trivial checksum | |
446 | adjustment, so make sure the current checksum is correct. */ | |
447 | if (nf_ip_checksum(*pskb, hooknum, hdrlen, 0)) | |
448 | return 0; | |
449 | ||
450 | /* Must be RELATED */ | |
451 | NF_CT_ASSERT((*pskb)->nfctinfo == IP_CT_RELATED || | |
452 | (*pskb)->nfctinfo == IP_CT_RELATED+IP_CT_IS_REPLY); | |
453 | ||
454 | /* Redirects on non-null nats must be dropped, else they'll | |
e905a9ed YH |
455 | start talking to each other without our translation, and be |
456 | confused... --RR */ | |
5b1158e9 JK |
457 | if (inside->icmp.type == ICMP_REDIRECT) { |
458 | /* If NAT isn't finished, assume it and drop. */ | |
459 | if ((ct->status & IPS_NAT_DONE_MASK) != IPS_NAT_DONE_MASK) | |
460 | return 0; | |
461 | ||
462 | if (ct->status & IPS_NAT_MASK) | |
463 | return 0; | |
464 | } | |
465 | ||
466 | DEBUGP("icmp_reply_translation: translating error %p manp %u dir %s\n", | |
467 | *pskb, manip, dir == IP_CT_DIR_ORIGINAL ? "ORIG" : "REPLY"); | |
468 | ||
469 | if (!nf_ct_get_tuple(*pskb, | |
470 | (*pskb)->nh.iph->ihl*4 + sizeof(struct icmphdr), | |
471 | (*pskb)->nh.iph->ihl*4 + | |
e905a9ed YH |
472 | sizeof(struct icmphdr) + inside->ip.ihl*4, |
473 | (u_int16_t)AF_INET, | |
474 | inside->ip.protocol, | |
475 | &inner, | |
476 | l3proto, | |
5b1158e9 | 477 | __nf_ct_l4proto_find((u_int16_t)PF_INET, |
e905a9ed | 478 | inside->ip.protocol))) |
5b1158e9 JK |
479 | return 0; |
480 | ||
481 | /* Change inner back to look like incoming packet. We do the | |
482 | opposite manip on this hook to normal, because it might not | |
483 | pass all hooks (locally-generated ICMP). Consider incoming | |
484 | packet: PREROUTING (DST manip), routing produces ICMP, goes | |
485 | through POSTROUTING (which must correct the DST manip). */ | |
486 | if (!manip_pkt(inside->ip.protocol, pskb, | |
487 | (*pskb)->nh.iph->ihl*4 + sizeof(inside->icmp), | |
488 | &ct->tuplehash[!dir].tuple, | |
489 | !manip)) | |
490 | return 0; | |
491 | ||
492 | if ((*pskb)->ip_summed != CHECKSUM_PARTIAL) { | |
493 | /* Reloading "inside" here since manip_pkt inner. */ | |
494 | inside = (void *)(*pskb)->data + (*pskb)->nh.iph->ihl*4; | |
495 | inside->icmp.checksum = 0; | |
496 | inside->icmp.checksum = | |
497 | csum_fold(skb_checksum(*pskb, hdrlen, | |
498 | (*pskb)->len - hdrlen, 0)); | |
499 | } | |
500 | ||
501 | /* Change outer to look the reply to an incoming packet | |
502 | * (proto 0 means don't invert per-proto part). */ | |
503 | if (manip == IP_NAT_MANIP_SRC) | |
504 | statusbit = IPS_SRC_NAT; | |
505 | else | |
506 | statusbit = IPS_DST_NAT; | |
507 | ||
508 | /* Invert if this is reply dir. */ | |
509 | if (dir == IP_CT_DIR_REPLY) | |
510 | statusbit ^= IPS_NAT_MASK; | |
511 | ||
512 | if (ct->status & statusbit) { | |
513 | nf_ct_invert_tuplepr(&target, &ct->tuplehash[!dir].tuple); | |
514 | if (!manip_pkt(0, pskb, 0, &target, manip)) | |
515 | return 0; | |
516 | } | |
517 | ||
518 | return 1; | |
519 | } | |
520 | EXPORT_SYMBOL_GPL(nf_nat_icmp_reply_translation); | |
521 | ||
522 | /* Protocol registration. */ | |
523 | int nf_nat_protocol_register(struct nf_nat_protocol *proto) | |
524 | { | |
525 | int ret = 0; | |
526 | ||
527 | write_lock_bh(&nf_nat_lock); | |
528 | if (nf_nat_protos[proto->protonum] != &nf_nat_unknown_protocol) { | |
529 | ret = -EBUSY; | |
530 | goto out; | |
531 | } | |
532 | nf_nat_protos[proto->protonum] = proto; | |
533 | out: | |
534 | write_unlock_bh(&nf_nat_lock); | |
535 | return ret; | |
536 | } | |
537 | EXPORT_SYMBOL(nf_nat_protocol_register); | |
538 | ||
539 | /* Noone stores the protocol anywhere; simply delete it. */ | |
540 | void nf_nat_protocol_unregister(struct nf_nat_protocol *proto) | |
541 | { | |
542 | write_lock_bh(&nf_nat_lock); | |
543 | nf_nat_protos[proto->protonum] = &nf_nat_unknown_protocol; | |
544 | write_unlock_bh(&nf_nat_lock); | |
545 | ||
546 | /* Someone could be still looking at the proto in a bh. */ | |
547 | synchronize_net(); | |
548 | } | |
549 | EXPORT_SYMBOL(nf_nat_protocol_unregister); | |
550 | ||
551 | #if defined(CONFIG_IP_NF_CONNTRACK_NETLINK) || \ | |
552 | defined(CONFIG_IP_NF_CONNTRACK_NETLINK_MODULE) | |
553 | int | |
554 | nf_nat_port_range_to_nfattr(struct sk_buff *skb, | |
555 | const struct nf_nat_range *range) | |
556 | { | |
557 | NFA_PUT(skb, CTA_PROTONAT_PORT_MIN, sizeof(__be16), | |
558 | &range->min.tcp.port); | |
559 | NFA_PUT(skb, CTA_PROTONAT_PORT_MAX, sizeof(__be16), | |
560 | &range->max.tcp.port); | |
561 | ||
562 | return 0; | |
563 | ||
564 | nfattr_failure: | |
565 | return -1; | |
566 | } | |
567 | EXPORT_SYMBOL_GPL(nf_nat_port_nfattr_to_range); | |
568 | ||
569 | int | |
570 | nf_nat_port_nfattr_to_range(struct nfattr *tb[], struct nf_nat_range *range) | |
571 | { | |
572 | int ret = 0; | |
573 | ||
574 | /* we have to return whether we actually parsed something or not */ | |
575 | ||
576 | if (tb[CTA_PROTONAT_PORT_MIN-1]) { | |
577 | ret = 1; | |
578 | range->min.tcp.port = | |
579 | *(__be16 *)NFA_DATA(tb[CTA_PROTONAT_PORT_MIN-1]); | |
580 | } | |
581 | ||
582 | if (!tb[CTA_PROTONAT_PORT_MAX-1]) { | |
583 | if (ret) | |
584 | range->max.tcp.port = range->min.tcp.port; | |
585 | } else { | |
586 | ret = 1; | |
587 | range->max.tcp.port = | |
588 | *(__be16 *)NFA_DATA(tb[CTA_PROTONAT_PORT_MAX-1]); | |
589 | } | |
590 | ||
591 | return ret; | |
592 | } | |
593 | EXPORT_SYMBOL_GPL(nf_nat_port_range_to_nfattr); | |
594 | #endif | |
595 | ||
596 | static int __init nf_nat_init(void) | |
597 | { | |
598 | size_t i; | |
599 | ||
600 | /* Leave them the same for the moment. */ | |
601 | nf_nat_htable_size = nf_conntrack_htable_size; | |
602 | ||
603 | /* One vmalloc for both hash tables */ | |
604 | bysource = vmalloc(sizeof(struct list_head) * nf_nat_htable_size); | |
605 | if (!bysource) | |
606 | return -ENOMEM; | |
607 | ||
608 | /* Sew in builtin protocols. */ | |
609 | write_lock_bh(&nf_nat_lock); | |
610 | for (i = 0; i < MAX_IP_NAT_PROTO; i++) | |
611 | nf_nat_protos[i] = &nf_nat_unknown_protocol; | |
612 | nf_nat_protos[IPPROTO_TCP] = &nf_nat_protocol_tcp; | |
613 | nf_nat_protos[IPPROTO_UDP] = &nf_nat_protocol_udp; | |
614 | nf_nat_protos[IPPROTO_ICMP] = &nf_nat_protocol_icmp; | |
615 | write_unlock_bh(&nf_nat_lock); | |
616 | ||
617 | for (i = 0; i < nf_nat_htable_size; i++) { | |
618 | INIT_LIST_HEAD(&bysource[i]); | |
619 | } | |
620 | ||
621 | /* FIXME: Man, this is a hack. <SIGH> */ | |
622 | NF_CT_ASSERT(nf_conntrack_destroyed == NULL); | |
623 | nf_conntrack_destroyed = &nf_nat_cleanup_conntrack; | |
624 | ||
625 | /* Initialize fake conntrack so that NAT will skip it */ | |
626 | nf_conntrack_untracked.status |= IPS_NAT_DONE_MASK; | |
627 | ||
628 | l3proto = nf_ct_l3proto_find_get((u_int16_t)AF_INET); | |
629 | return 0; | |
630 | } | |
631 | ||
632 | /* Clear NAT section of all conntracks, in case we're loaded again. */ | |
633 | static int clean_nat(struct nf_conn *i, void *data) | |
634 | { | |
635 | struct nf_conn_nat *nat = nfct_nat(i); | |
636 | ||
637 | if (!nat) | |
638 | return 0; | |
639 | memset(nat, 0, sizeof(nat)); | |
640 | i->status &= ~(IPS_NAT_MASK | IPS_NAT_DONE_MASK | IPS_SEQ_ADJUST); | |
641 | return 0; | |
642 | } | |
643 | ||
644 | static void __exit nf_nat_cleanup(void) | |
645 | { | |
646 | nf_ct_iterate_cleanup(&clean_nat, NULL); | |
647 | nf_conntrack_destroyed = NULL; | |
648 | vfree(bysource); | |
649 | nf_ct_l3proto_put(l3proto); | |
650 | } | |
651 | ||
652 | MODULE_LICENSE("GPL"); | |
653 | ||
654 | module_init(nf_nat_init); | |
655 | module_exit(nf_nat_cleanup); |